I just put together a short SCP about a special fungus that turns a person's body into an incubator for ducks. It was inspired by a photo I saw on imgur a couple of days ago. Please critique! My sandbox: Duck face tab

When there are more than fifty adult specimens present a cull should be carried out until no more than twenty and no less than ten adult specimens of equal gender diversity remain.

You need a comma after "present", and you can reduce the rest of the sentence to "until 10-20 male and female specimens remain". Don't write more than you need to communicate the idea.

Anyone infected by SCP-XXXX spores is to be detained and quarantined without delay, and when they expire their body is to be incinerated.

Needs comma after "expire". You'd actually probably do better to separate that into two sentences, with a period after "delay" and no "and". You still need the comma.

Basically, repeat this throughout the document and proofread it for lack of punctuation.

Other than that: Your length is good (short works!), your concept is fantastic. Your issues are the writing thing mentioned above, and the picture. First of all, that's not what mallard ducklings look like. Second of all, are you sure you own that? Do you have the rights to it? Are you sure you're allowed to use it?

I tightened up the language as suggested, and fixed a few other minor typos. I added commas throughout to make it flow better. I also changed from mallards to just ducks, so the ducklings in the picture match the species.

I've tracked down the source of the image and contacted the original poster to get permission, but it's not a big deal if the image can't be used.

I finally got around to posting this to the Wiki. After waiting about a month I still haven't heard back from the person who posted the image relevant to the SCP, so I decided to just go ahead and post. Thanks again for feedback!